ZZ 502 Engine
 

I saw some posts a while ago but is anyone running a GM ZZ 502 crate engine without any problems. I will be running a fresh water cooling system. Thanks

I have a friend who bought one, cam will revert IF your not running dry exhaust, we changed cam and tuned rich on dyno, #3 cylinder seemed to be the leanest with that intake and if I remember right, motor made about best power with those E heads at 32 or so degrees of timing. As far as "clearances", he bought motor slightly used with a ate cam gear but did NOT open up anything internally and its been fine, Smitty

I had one in my 272 and definitely evidence of reversion even with headers dry to near the tip. Otherwise a solid mule torque monster.

I have been wondering why such mild cam reverts, must be the late exh valve closing with 108icl. In marine aplication i would use 102 or 104icl instead of 108. Zz502 cam aint that far from crane 731.

A friend of mine ran ZZ502 for 5 years in his Baja with no problems at all,,factory merc. exhaust system,